Japanese Patent Application Publication No. 10-173984 (Patent Document 1) discloses an electronic still camera configured to detect changes in attitude of the camera using a vertical orientation detecting sensor to allow an image to be seen always in an upright state according to the detected changes in attitude. Japanese Patent Application Publication No. 2004-240478 (Patent Document 2) discloses a portable electronic device configured to determine the attitude of the device using a gyro chip to allow an image to be seen always in an upright state according to changes in attitude of the device.